Rosalia longicorn — Rosalia alpina (Linnaeus)

Beetles (Coleoptera) are the most numerous insect group and the largest group of living beings on the planet, with about 400,000 described species to date. Of that number, around 29,000 are distributed in Europe, but there are no reliable data on the number of species in Bosnia and Herzegovina. The National Museum hosts one of the largest and most important collections of these insects in the Balkans.

Saproxylic beetles are so-called because they depend, in at least some part of their life cycle, on dead or dying trees and fallen wood. There are a number of endangered saproxylic species which, because of their dependence on old trees in forests, are sensitive to changes in their habitats and are therefore used as indicators of the level of preservation of these ecosystems.

Among them is the rosalia longicorn (Rosalia alpina), one of the most beautiful species in this area, which mostly inhabits mountain beech forests. It is recognisable by its distinct light blue colour and large black spots, which afford it excellent camouflage on the bark of beech trees. It is still frequently encountered in Bosnia and Herzegovina, but it is increasingly coming under threat because of deforestation.